import assert from "node:assert/strict";
import test from "node:test";
import { ARENA_STAGES, VALIDATED_ARENA_STAGES, chooseArenaStage } from "./arena-stages.mjs";

test("the rated pool contains all eight validated arenas", () => {
  assert.equal(ARENA_STAGES.length, 8);
  assert.deepEqual(VALIDATED_ARENA_STAGES.map((stage) => stage.id), ARENA_STAGES.map((stage) => stage.id));
});

test("rated selection covers the pool uniformly and avoids the previous arena", () => {
  const choices = VALIDATED_ARENA_STAGES.map((_, index, pool) => (
    chooseArenaStage({ random: () => (index + 0.25) / pool.length })
  ));
  assert.deepEqual(choices.map((stage) => stage.id), VALIDATED_ARENA_STAGES.map((stage) => stage.id));

  const previousStageId = VALIDATED_ARENA_STAGES[0].id;
  for (let index = 0; index < VALIDATED_ARENA_STAGES.length - 1; index += 1) {
    const selected = chooseArenaStage({
      previousStageId,
      random: () => (index + 0.25) / (VALIDATED_ARENA_STAGES.length - 1),
    });
    assert.notEqual(selected.id, previousStageId);
  }
});